1. Field of the Invention
The present invention relates to an apparatus for generating a fluid jet and a system for venting a container incorporating the apparatus. In particular, the present invention relates to an apparatus for generating a pulsed jet of fluid upon initiation of a propellant and a venting system incorporating the apparatus.
2. Description of Related Art
Energetic materials, such as explosives and propellants, are often found in confined spaces, for example, within munitions. Under normal conditions, these materials are unlikely to explode or burn spontaneously; however, many are sensitive to heat and mechanical shock. For example, when exposed to extreme heat (as from a fire) or when impacted by bullets or fragments from other munitions, the energetic materials may be initiated, causing the munitions, in which the energetic materials are disposed, to inadvertently explode prematurely. Conventionally, armor is used to protect munitions and other energetic material-containing devices from being impacted by bullets, fragments, or other such projectiles. Armor is, however, heavy by nature and may not be suitable for some implementations, such as in mobile containers for munitions.
Efforts have been made to develop “insensitive munitions,” which are munitions that are generally incapable of detonation except in their intended missions to destroy a target. In other words, if fragments from an explosion strike an insensitive munition, if a bullet impacts the munition, or if the munition is in close proximity to a target that is hit, it is less likely that the munition will detonate. Similarly, if the munition is exposed to extreme temperatures, as from a fire, the munition will likely only burn, rather than explode.
One way that munitions have been made more insensitive is by developing new explosives and propellants that are less likely to be initiated by heating and/or inadvertent impact. Such materials, however, are typically less energetic and, thus, may be less capable of performing their intended task. For example, a less energetic explosive may be less capable of destroying a desired target than a more energetic explosive. As another example, a less energetic propellant may produce less thrust than a more energetic propellant, thus reducing the speed and/or the range of the munition. Additionally, the cost to verify and/or qualify new explosives and/or propellants, from inception through arena and system-level testing, can be substantial when compared to improving the insensitive munition compliance of existing explosives and/or propellants.
Another way to make a munition more insensitive is to rapidly vent the container in which the explosive or propellant is stored, so that pressure cannot build up when the munition is exposed to an unplanned external stimulant, such as a fire, a bullet impact or a fragment impact. If pressure is not allowed to build up, the energetic material will burn rather than detonate. Accordingly, a system has been developed that uses a cutting charge, such as a linear shaped charge, to selectively vent a container in which an energetic material is disposed. Such systems, however, may not be suitable for use with highly energetic materials because temperatures associated with the cutting charges may be sufficient to detonate the energetic material disposed in the container.
While there are many ways known in the art to render munitions more insensitive, considerable room for improvement remains. The present invention is directed to overcoming, or at least reducing, the effects of one or more of the problems set forth above.